Induction displacement unit

ABSTRACT

An induction displacement unit comprising an induction plenum comprising a plurality of first nozzles communicating with a first discharge plenum and a plurality of second nozzles communicating with a second discharge plenum, a return air plenum, a heating coil disposed between the return air plenum and the first discharge plenum, a cooling coil disposed between the return air plenum and the second discharge plenum, the induction plenum vertically disposed between the heating coil and the cooling coil, the heating coil disposed in an upper portion of the unit, the first discharge plenum disposed to induce a substantially vertical discharge, and the second discharge plenum disposed to induce a substantially horizontal discharge.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/140,256, entitled “INDUCTION DISPLACEMENT UNIT,” filed Sep. 24, 2018,which is a continuation of U.S. patent application Ser. No. 14/211,179,entitled “INDUCTION DISPLACEMENT UNIT,” filed Mar. 14, 2014, now U.S.Pat. No. 10,088,179, which is a continuation of U.S. patent applicationSer. No. 13/771,199, entitled “INDUCTION DISPLACEMENT AIR HANDLINGUNIT,” filed Feb. 20, 2013, now U.S. Pat. No. 9,625,166, which issued onApr. 18, 2017, each of which is hereby incorporated by reference in itsentirety for all purposes.

FIELD OF THE INVENTION

The invention relates to an induction displacement unit, and moreparticularly, to an induction displacement unit comprising an inductionplenum communicating with a first discharge plenum and a seconddischarge plenum, the first discharge plenum in communication with aheating coil and the second discharge plenum in communication with acooling coil.

BACKGROUND OF THE INVENTION

Displacement ventilation systems are in wide spread use in the HVACindustry. One particular application for such systems is in educationalbuildings. Typically, a number of displacement air terminal devices willbe located along a perimeter wall of a classroom space and areconfigured to deliver ventilation air to the space, see FIG. 1.

Displacement ventilation (DV) is an air distribution system designed tosimultaneously improve indoor air quality and reduce energy use. Cool,rather than cold supply air is provided directly to occupants throughlow mounted diffusers. Heat generated by the occupants and equipment inthe space causes ventilation air to be naturally drawn up by convectionwhich ensures fresh air is continually delivered to the breathing zoneof the occupants. The warm air continues to rise and contaminants arecarried away towards the ceiling exhaust, resulting in improved indoorair quality near the occupants. Schools, restaurants, theaters, atria,other open spaces with high ceilings, and spaces where air quality is aconcern are excellent applications.

In addition to the displacement function, it is also known to configuredisplacement devices to have induction nozzles. By adding induction,room air from the space can be conditioned, filtered, and returned tothe space in a mixture with the ventilation air. This type of unit issometimes referred to as an induction-displacement unit. In this type ofsystem, a coil is provided in the return air path of theinduction-displacement unit to condition the return air, as necessary.In the cooling mode, the coil will reduce the return air temperature toa few degrees below the space temperature. In the heating mode, the coilmay be set to raise the temperature of the return air such that thedelivered air has a higher temperature than that of the air in the room.

In each mode a space temperature set point can be maintained, however,in heating mode, the induction-displacement unit can no longer functionas a displacement terminal unit due to the fact that the delivered airstarts rising as soon as it leaves the unit instead of pooling acrossthe floor. To prevent placing an induction-displacement unit in theheating mode, a separate heating system can be provided in the space,such as fin-tube radiation or radiant panels. However, as theinduction-displacement units are placed along at least one wall of thespace, such heating systems cannot be placed in the same location. Thisis especially troublesome where the induction-displacement units arelocated along an exterior wall of the space because this is the locationwhere heating is generally most needed. As such, improvements aredesired for induction-displacement units that can simultaneously provideheating to an exterior wall of a space and provide displacementventilation air to the occupied area of the space.

Representative of the art is U.S. Publication No. 2012/0270494 whichdiscloses an induction-displacement neutral wall air terminal unitincludes a housing defining a supply airflow path, a connected returnairflow path, and a heating airflow path separated from the supply andreturn airflow paths by at least one interior wall. The unit alsoincludes a plurality of induction-type nozzles located within the supplyairflow path, that are deliver a ventilation air flow stream into thesupply air flow path. The nozzles induce a return air flow streamthrough the return air flow path that mixes with the ventilation airflow stream to form a supply air flow stream delivered to a supply airoutlet. A heating element is disposed within the heating airflow path toheat air within the heating air flow path. A plurality of fans may beplaced within the heating airflow path to increase the overall heatingcapacity of the unit.

What is needed is an induction displacement unit comprising an inductionplenum communicating with a first discharge plenum and a seconddischarge plenum, the first discharge plenum in communication with aheating coil and the second discharge plenum in communication with acooling coil. The present invention meets this need.

SUMMARY OF THE INVENTION

The primary aspect of the invention is to provide an inductiondisplacement unit comprising an induction plenum communicating with afirst discharge plenum and a second discharge plenum, the firstdischarge plenum in communication with a heating coil and the seconddischarge plenum in communication with a cooling coil.

Other aspects of the invention will be pointed out or made obvious bythe following description of the invention and the accompanyingdrawings.

The invention comprises an induction displacement unit comprising aninduction plenum comprising a plurality of first nozzles communicatingwith a first discharge plenum and a plurality of second nozzlescommunicating with a second discharge plenum, a return air plenum, aheating coil disposed between the return air plenum and the firstdischarge plenum, a cooling coil disposed between the return air plenumand the second discharge plenum, the induction plenum verticallydisposed between the heating coil and the cooling coil, the heating coildisposed in an upper portion of the unit, the first discharge plenumdisposed to induce a substantially vertical discharge, and the seconddischarge plenum disposed to induce a substantially horizontaldischarge.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, illustrate preferred embodiments of the presentinvention, and together with a description, serve to explain theprinciples of the invention.

FIG. 1 is a perspective view of a conditioned space with two inventiveunits.

FIG. 2 is a perspective cut-away view of an inventive unit.

FIG. 3 is a cross-sectional view of an inventive unit.

FIG. 4 is a cross-sectional view of an alternate embodiment of theinventive unit.

FIG. 5A is a perspective cut-away view of the inventive unit.

FIG. 5B is a detail of FIG. 5A.

FIG. 6 is a cross-sectional view showing the cooling air flow path.

FIG. 7 is a cross-sectional view showing the heating air flow path.

FIG. 8 is a conditioned space temperature profile in heating mode usingthe inventive unit.

FIG. 9 is a conditioned space temperature profile in cooling mode usingthe inventive unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a perspective view of a conditioned space such as a classroomwith two inventive units. Units 100 are typically installed along anexterior wall. The wall displacement unit can be utilized in buildingair-conditioning systems with air handlers, chilled water circuits, andhot water boiler systems.

FIG. 2 is a perspective cut-away view of an inventive unit. Eachinventive wall displacement unit 100 receives a constant volume ofpressurized prime air flow comprising conditioned outside air at supplyair temperatures, typically in the range of approximately 50° F. to 70°F., through the prime air inlet opening 10. The prime air is pressurizedas it enters the unit.

FIG. 3 is a cross-sectional view of an inventive wall displacement unit.The unit housing comprises a top 40 to which grille 21 is mounted.Panels 41, 42, 43, 44 typically comprise the side of the unit adjacentthe wall 19. Side panels 45, 46 complete the unit.

Wall displacement unit 100 comprises an induction plenum 11 and a coilfor air heating 12 and a coil for air cooling 13. Induction plenum 11 isvertically disposed between the heating coil 12 and the cooling coil 13in a stacked arrangement. Heating coil 12 is vertically disposed in anupper portion of the unit while the cooling coil 13 is disposed belowthe elevation of the heating coil 12. This vertical configuration takesadvantage of the buoyant (lower density) nature of warmer air whencompared to cooler air. Induction plenum 11 further comprises aplurality of air injection nozzles 14, 15 in communication withdischarge plenum 20 and discharge plenum 18 respectively.

Air from the induction plenum 11 flows through nozzles 14, 15 therebyinducing a return flow of room air from the conditioned room (R) intothe return air plenum 16. A portion of the returned room air flowsthrough cooling coil 13 thereby reconditioning the return room air priorto mixing with the primary air jets in the lower discharge plenum 18.The return air is then discharged at low velocity as supply air throughthe lower part of the perforated front cover, 17 and 17A, in asubstantially horizontal direction when in cooling mode operation.

In heating mode operation, the supply air discharged through the lowerpart of the front cover 17, see 17A, delivers prime ventilation air atnear room temperature. The main source for heat load neutralization of acold outside wall or window 19 is the upper heating coil 12. Thereturned room air flows through heating coil 12 to recondition the roomair prior to discharge through grille 21. The reconditioned room air isthen mixed with the primary air jets from nozzles 14 in the upperdischarge plenum 20. Nozzles 14 discharge in a generally upwarddirection. Nozzles 15 discharge in a generally downward direction.Discharge plenum 20 is in an upper portion of the unit so as tofacilitate an upward or substantially vertical air flow.

Heating coil 12, disposed in an uppermost portion of the unit, heats theair and when mixed with the air flow from nozzles 14 elevates thetemperature of the return air entering the coil from the return plenum16, thereby causing forced convection. Heated air is discharged upwardthrough the grill 21 on top of the unit. Upon exiting grille 21 theheated air rises along the perimeter wall 19 and window 22 to create abuilding heating load neutralizing warm air curtain.

Each unit can be sized to fit under a sill adjacent to the perimeterwall 19 mounted to the floor 23 or wall 19. The unit provides spacingfor connecting hardware 24 on both sides of the unit inside the housing.Although the unit is designed for use in new buildings, it can also beused for refurbishing existing high-pressure induction systems.

FIG. 4 is a cross-sectional view of an alternate embodiment of theinventive unit. In this alternate embodiment induction plenum 11 of unit200 receives a constant volume of pressurized prime air flow ofconditioned outside air at supply air temperatures, typicallyapproximately 50° F. to 70° F., through the prime air inlet opening 10.Unit 200 comprises an induction plenum 11 and separate coils 13 forcooling. The cooling supply air stream is separated into two distinctiveplenum sections, a main lower discharge plenum 110 and a secondary lowerdischarge plenum 111. Plenums 110 and 111 are separated by wall member112. Plenum section 110 provides a high induced flow and plenum section111 adds required ventilation air to the induced flow. Both flows exitthe unit in a substantially horizontal direction.

FIG. 5A is a perspective cut-away view of the inventive unit. Unit 100receives a constant volume of pressurized prime air flow of conditionedventilation air at prime air temperatures, typically in the range ofapproximately 50° F. to 70° F., through the prime air inlet opening 10.Unit 100 is equipped with air damper 25 to control the ventilation airvolume. In FIG. 5B, damper 25 is connected to inlet opening 10. Damper25 operates with the building control system (not shown) and reduces orshuts off the primary air flow to the induction plenum 11 when demand islow, for example, when the building is unoccupied. When demand isreduced it is also possible to operate just one or two units when apartial load is required thereby shutting off other units in the system.

Unit 100 further comprises water control valves 26, 27. Valve 26controls hot water flow from a boiler (not shown) to the heating coil12. Valve 27 controls cold water flow from a chiller (not shown) to thecooling coil 13. A thermostat (not shown) in the conditioned spacecontrols the room temperature by controlling operation of the watercircuits entering the coils through the water control valves 26, 27. Theheating and cooling coils may be controlled by either a two-way watervalves 26, 27 or alternatively with three-way water valves.

FIG. 6 is a cross-sectional view showing the cooling air flow path. Roomreturn air 28 enters the upper part of the housing, thereby entering thereturn air plenum 16. In this example heating coil 12 is shutoff becauseit does not operate during a cooling season. Induction nozzles 14, 15located on the induction plenum 11 are pressurized by prime air atapproximately 0.25″ to 1.0″ w.g and a temperature in the range ofapproximately 55° F. to 58° F. Discharge of the positive pressure airthrough the nozzles 15 induces a flow of return air 28B through coolingcoil 13. Conditioned return air leaving cooling coil 13 at approximately68° F. mixes with the prime air at approximately 55° F. in the dischargeplenum 18. The prime air entering the induction plenum 11 is conditionedby an outdoor air handler known in the art (not shown). Mixed air (65°F.) 29 is discharged through the lower discharge plenum 18 into the roomin a substantially horizontal direction 29.

In this embodiment the inlet air flow is received into the unit throughthe front of the unit 17. A portion of the inlet flow is divertedthrough the heating coil 12 and a portion through the cooling coil 13.In particular, since heating coil 12 and cooling coil 13 are immediatelyadjacent the induction plenum the primary air discharged from theinduction plenum 11 through nozzles 14, 15 is efficiently used to inducean air flow for both heating 31 through heating coil 12 and for cooling29 through cooling coil 13. This configuration does not require fans tomove the air through the unit.

FIG. 7 is a cross-sectional view showing the heating air flow path. Roomair 30 at approximately 70° F. to 72° F. enters the upper part of thehousing, thereby entering return air plenum 16. Cooling coil 13 istypically shutoff and does not operate during a heating season.Induction nozzles 14, 15 located on the induction plenum 11 arepressurized by prime air at approximately 0.25″ to 1.0″ w.g. Dischargeof the positive pressure prime air through nozzles 14 induces a flow ofreturn air through heating coil 12 which is at a temperature ofapproximately 120° F. to 180° F. The conditioned air leaves the heatingcoil at a temperature in the range of approximately 90° F. to 105° F.and thereafter mixes with the conditioned prime air at approximately 65°F. Heating coil 12 may comprise a hydronic or water heating element, asteam heating element, or an electric heating element. The mixed air ata temperature of approximately 85° F. to 90° F. is discharged throughthe upper discharge plenum 20 through grill 21 into the conditioned roomin a substantially vertical direction 31.

The mass flow of the discharged heating supply air can be adjusted bythe quantity of nozzles 14 dedicated to heating. The air curtain createdby discharge 31 in front of a window or cold wall is configured to rollthe air within the adjacent area of the perimeter wall, and not todisturb the stratification created by the displacement ventilation. Themass flow, and therefore the quantity of nozzles 14 dedicated toheating, can be customized to accommodate 120° F., 140° F. and 180° F.water entering from a boiler (not shown).

Cooling coil 13 is not operating during the heating season, but primeair pressurizing at approximately 0.25″ to 1.0″ w.g. induction nozzles15 causes the return air 30B to be drawn through the cooling coil 13.Return air leaving the cooling coil, at approximately 72° F., will mixwith the conditioned prime air at approximately 65° F. The mixed air 32at approximately 68° F. is discharged through the lower discharge plenum18 in a substantially horizontal direction.

The unit provides at least 8,000 btuh of heating through the heatingairflow path when the heating coil 12 is served by hot water having atemperature of approximately 180° F. The unit can be configured tooperate in a heating mode wherein the heating coil 12 provides heatedair through the heating airflow path; and a ventilation mode wherein theunit provides a supply airflow stream having a temperature of about 53°F. The heating mode can be simultaneously activated with a ventilationmode.

The number and diameter of nozzles 14 can be selected based upon thetemperature of the water entering the heating coil 12. The numericvalues included in this description are not intended to limit the scopeof the invention and are provided as examples only.

Assuming a total of 42 nozzles (14), the diameters are:

Entering Water Nozzle diameter Temperature [° F.] [inches] 120 0.140 1400.188 180 0.250

Assuming a nozzle diameter of 0.188 inches the nozzle quantities are:

Entering Water Nozzle Temperature [° F.] quantity 120 32 140 42 180 56

In operation, the inventive unit creates a simultaneous mixing heatingcurtain neutralizing cold perimeter loads while utilizing displacementventilation for the inner occupied space. The inventive inductiondisplacement wall unit also meets the noise requirements of ANSIStandard S12.60, which is advantageous in applications where reducednoise is desirable, such as in school classrooms.

In operation the unit provides a method of conditioning a space using aninduction displacement unit. The unit induces a return air flow into theunit by discharging pressurized air within the unit. The return air flowstream comprises a single stream of air entering the unit through thefront of the unit. The unit induces a portion of the return air flowstream 28 to flow through a heating coil and induces a portion of thereturn air flow stream 28B to flow through a cooling coil. The unitdischarges the air flow from the heating coil in a substantiallyvertical direction. The unit discharges the air flow from the coolingcoil in a substantially horizontal direction.

FIG. 8 is a conditioned space temperature profile in heating mode usingthe inventive unit. The unit provides uniform distribution ofconditioned air to the space. The heated air is evenly distributedthrough the space while cool air is drawn to the unit along the floor.

FIG. 9 is a conditioned space temperature profile in cooling mode usingthe inventive unit. The unit provides uniform distribution ofconditioned air to the space. The chilled air is evenly distributedthrough the space while hot air is drawn to the unit along the ceiling.

Although a form of the invention has been described herein, it will beobvious to those skilled in the art that variations may be made in theconstruction and relation of parts without departing from the spirit andscope of the invention described herein.

1. An induction displacement unit of a heating, ventilation, and/or airconditioning (HVAC) system, the induction displacement unit comprising:a housing having a side and a discharge outlet formed in the side; adischarge plenum formed in the housing and communicatively coupled withthe discharge outlet; an induction plenum; a nozzle configured to directa primary air flow from the induction plenum into the discharge plenumsuch that the primary air flow induces a return air flow into thedischarge plenum, the primary air flow and the return air flow form amixed air flow in the discharge plenum, and the mixed air flow isdirected from the discharge plenum through the discharge outlet; and aheat exchange coil disposed in an interior of the housing between theinduction plenum and the side of the housing and configured to conditiona temperature of the return air flow.
 2. The induction displacement unitof claim 1, wherein the side of the housing extends in a horizontaldirection and the heat exchange coil overlaps with the side of thehousing and the induction plenum along the horizontal direction.
 3. Theinduction displacement unit of claim 1, comprising a return air plenumformed in the housing such that the return air flow is directed throughthe return air plenum, over the heat exchange coil, and into thedischarge plenum.
 4. The induction displacement unit of claim 3, whereinthe return air plenum is formed along an additional side of the housingcoupled to the side of the housing.
 5. The induction displacement unitof claim 1, wherein the nozzle is configured to direct the primary airflow from the induction plenum into the discharge plenum in a verticaldirection, such that the primary air flow induces the return air flowinto the discharge plenum in a horizontal direction substantiallyperpendicular to the vertical direction.
 6. The induction displacementunit of claim 1, wherein the heat exchange coil is configured to receivea liquid to generate a heat exchange relationship between the liquid andthe return air flow.
 7. The induction displacement unit of claim 6,comprising a valve configured to: open to enable the heat exchange coilto receive the liquid; and close to block the heat exchange coil fromreceiving the liquid.
 8. An induction displacement unit of a heating,ventilation, and/or air conditioning (HVAC) system, the inductiondisplacement unit comprising: a housing having a side and a dischargeoutlet formed in the side, wherein the side of the housing extends in ahorizontal direction; a discharge plenum formed in the housing andcommunicatively coupled with the discharge outlet; an induction plenum;a nozzle configured to direct a primary air flow from the inductionplenum into the discharge plenum such that the primary air flow inducesa return air flow into the discharge plenum and a mixture of the primaryair flow and the return air flow is output from the discharge plenumthrough the discharge outlet; and a heat exchange coil disposed in aninterior of the housing such that the heat exchange coil overlaps withthe induction plenum, the discharge plenum, and the discharge outletalong the horizontal direction, wherein the heat exchange coil isconfigured to condition a temperature of the return air flow.
 9. Theinduction displacement unit of claim 8, comprising a return air plenumformed in the housing such that the heat exchange coil is positionedbetween the return air plenum and the discharge plenum, wherein thenozzle is configured to direct the primary air flow from the inductionplenum into the discharge plenum such that the primary air flow inducesthe return air flow into the return air plenum, over the heat exchangecoil, and into the discharge plenum.
 10. The induction displacement unitof claim 9, wherein the return air plenum is formed along an additionalside of the housing coupled to the side of the housing.
 11. Theinduction displacement unit of claim 8, wherein the nozzle is configuredto direct the primary air flow from the induction plenum into thedischarge plenum in a vertical direction substantially perpendicular tothe horizontal direction.
 12. The induction displacement unit of claim8, wherein the heat exchange coil is configured to receive water togenerate a heat exchange relationship between the water and the returnair flow.
 13. The induction displacement unit of claim 12, wherein theheat exchange coil is disposed upstream of the discharge plenum relativeto a direction of the return air flow,
 14. An induction displacementunit of a heating, ventilation, and/or air conditioning (HVAC) system,the induction displacement unit comprising: a housing defining a housinginterior; a discharge outlet formed in a side of the housing andconfigured to output a mixed air flow from the housing interior, whereinthe side of the housing extends in a horizontal direction; a dischargeplenum formed in the housing interior defined by the housing; aninduction plenum; a heat exchange coil disposed in the housing interior;and a nozzle configured to direct a pressurized air flow from theinduction plenum and into the discharge plenum such that the pressurizedair flow induces a return air flow over the heat exchange coil and intothe discharge plenum, wherein a combination of the pressurized air flowand the return air flow forms the mixed air flow in the dischargeplenum.
 15. The induction displacement unit of claim 14, wherein theheat exchange coil is disposed in the housing interior such that theheat exchange coil overlaps with the induction plenum and the dischargeoutlet along the horizontal direction.
 16. The induction displacementunit of claim 14, comprising a return air plenum formed in the housinginterior such that the heat exchange coil is positioned between thereturn air plenum and the discharge plenum, wherein the nozzle isconfigured to direct the pressurized air flow from the induction plenuminto the discharge plenum such that the pressurized air flow induces thereturn air flow into the return air plenum, over the heat exchange coil,and into the discharge plenum.
 17. The induction displacement unit ofclaim 16, wherein the return air plenum is formed along an additionalside of the housing coupled to the side of the housing.
 18. Theinduction displacement unit of claim 14, wherein the nozzle isconfigured to direct the pressurized air flow in a vertical directionsubstantially perpendicular to the horizontal direction.
 19. Theinduction displacement unit of claim 14, wherein the heat exchange coiloverlaps with the induction plenum and the side of the housing along thehorizontal direction;
 20. The induction displacement unit of claim 15,comprising: a valve configured to: open to enable a flow of a liquidinto the heat exchange coil such that a heat exchange relationship isestablished between the liquid and the return air flow; and close toblock the flow of the liquid into the heat exchange coil; and a damperconfigured to: open to direct the pressurized air flow into theinduction plenum; and close to block the pressurized air flow into theinduction plenum.